Expanding the phenotypic and genetic landscape of congenital neutropenia through whole‐exome and genome sequencing

Abstract Congenital neutropenia (CN) comprises a heterogeneous group of rare genetic disorders. While some CN cases present only with neutropenia, others present with additional extra‐hematological manifestations. The most common cause of CN is variants in ELANE; however, approximately 30 other gene...

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Main Authors: Séverine Marti, Philippe Pellet, Blandine Beaupain, Léa Durix, Julien Buratti, Yves Réguerre, Nathalie Aladjidi, Saba Azarnoush, Severine Clauin, Wahid Abou Chahla, Gilles Blaison, Jeremy Bertand, Damien Bodet, Benoit Brethon, Jessica Chane‐Teng, Manon Delafoy, Chrystelle Dupraz, Virginie Gandemer, Philippe Denizeau, Alice Goldenberg, Pierre Hirsch, Anaïs l'Haridon, Aude Marie‐Cardine, Gabriella Vera, Brigitte Nelken, Laure Nizery, Marie Nolla, Marlène Pasquet, Jérémie Rosain, Louis Terriou, Isabelle Plo, Jean Donadieu, Christine Bellanné‐Chantelot
Format: Article
Language:English
Published: Wiley 2025-06-01
Series:HemaSphere
Online Access:https://doi.org/10.1002/hem3.70150
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Summary:Abstract Congenital neutropenia (CN) comprises a heterogeneous group of rare genetic disorders. While some CN cases present only with neutropenia, others present with additional extra‐hematological manifestations. The most common cause of CN is variants in ELANE; however, approximately 30 other genes have been implicated. Despite this, the genetic basis remains unknown in roughly 30% of cases. The clinical and genetic heterogeneity of CN makes diagnosis particularly challenging. To address this, we conducted exome or genome sequencing of 60 patients with a suspected diagnosis of CN that remained unresolved following targeted sequencing. A genetic diagnosis was established in 25 patients (42%). Variants were identified in 15 different genes. Half of these cases involved genes traditionally associated with hereditary immunodeficiencies (GINS4, CARD11, ADA2, GINS1, LCP1, SASH3, and WAS). One‐third of the cases carried variants in genes linked to syndromic disorders (VPS13B, TAFAZZIN, CLPB, and TONSL), demonstrating variable penetrance of extra‐hematological phenotypes. A smaller subset (15%) harbored variants in genes associated with inherited bone marrow failure syndromes (BLM, RPL18, SAMD9, and SRP72), identified incidentally due to atypical presentations. Compared to patients with ELANE‐CN, these individuals were diagnosed later, had fewer severe bacterial infections and gingivitis, exhibited less profound neutropenia, lacked monocytosis, and had a granulocytic maturation arrest, often beyond the promyelocytic stage. A shared feature among these cases was a tendency toward reduced lymphocyte subsets, particularly NK cells. This study highlights the significant contribution of exome and genome sequencing in diagnosing CN, given the phenotypic overlap, genetic heterogeneity, and variable penetrance of immunological and extra‐hematological features.
ISSN:2572-9241